Italian clinicians report the case of a three-year-old child with SMA type 1 who developed hemophagocytic lymphohistiocytosis (HLH) three days after an intravenous injection of onasemnogène aboparvovec (Zolgensma®).
- This rare immune complication was characterized by fever, skin rash, hepatosplenomegaly and biological disturbances (hypoplaketosis, leukopenia, increased LDH and D-dimer).
- The whole picture fulfilled the diagnostic criteria of HLH.
- The evolution was favorable after increasing the daily dose of corticosteroid therapy.
HLH is thus a new type of systemic complication of SMA gene therapy. It adds to the risk of liver failure and thrombotic microangiopathy (TMA), two previously reported adverse events.
